Abstract

With rising energy costs and the carbon tax implementation in Australia, businesses concern with respect to energy efficiency have increased. As their operating costs rise, many have opted to explore sustainable energy solutions which serve to combat/decrease the effect of these rises. So much so, that Balance Utility Solutions (B.U.S) was formed in 2011 to service the growing market for integrated and sustainable energy solutions. To exemplify their renewable edge, the company had opted to replace 20kW (base load) of grid supplied electricity, with renewable energy by 2015. With this project serving to cover 4kW of the opted renewable replacement.

The 4kW system was an auction purchase (2nd hand system, with 2 years previous use), of a lump sum of many different components/parts. The parts specified for this project were, 4kW’s of photovoltaic panels, 2 grid tied inverters, and 24 x 2V batteries (48V DC battery bank), with one bidirectional battery Inverter as a backup.

The original aim of this project was to analyse, plan and install the system, with the capability of supplying power to the office load during daylight hours, thus decreasing the amount of electricity purchased from Synergy.

Due to changes being made on the roof, and a significant relationship formed by B.U.S and a leading solar technology supplier, the aim was modified to;

Have all necessary documents, and plans ready and approved before the internship completion.

Have a system design that was able to supply power to the grid during daylight hours, and also have the capability to be disconnected from the grid, and used as part of an island test facility.

Therefore this report is a breakdown of the processes, analysis, and modifications that were made to achieve these aims. Furthermore, the report serves to satisfy the stakeholder’s key interests of;

Gaining an understanding of the systems components, with a greater emphasis on PV technology.

And having a financial analysis of their investment.

Key findings throughout the project were;

A system analysis output, with a generation of 7.171MWh/annually

A good payback period of 4.4 years, with an internal rate of return of 18.8%.

Having the PV panels face north, instead of 35°, E of N (original orientation of building/roof), has no significant effect on the systems output.

Having the panels sloped at 26° increased the incident annual solar radiation by 300kWh/m2/day, with respect to having them laid flat on the roof.

This system could not apply for Renewable Energy Credits (REC’s), due to it being 2nd hand.

Grid-tied inverters had transformers, however, the lack of galvanic isolation issues were negligible.

Professional engineers constantly deal with dynamic/changes in their projects, and have to be quick and efficient in adapting to these changes.